Analysis of NK differentiation potential and NK progenitor cell expansion mediated by HOXB4.

<p>(A) Percentages of NK cells (CD56⁺CD3⁻CD19⁻) among nucleated cells collected at the end of 5 weeks of co-culture. Cells derived from the 2 weeks primary co-cultures with MS-5/SP-HOXB4 or MS-5/EGFP were then plated on unmodified MS-5 cells in conditions known to promote NK-cell differentiation and maintained during three weeks. At the end of the culture period, cells were analyzed by FACS for the expression of CD56 and CD3/CD19 markers. Un-co-cultured hEB cells were directly cultured under NK-cell differentiation conditions for 3 weeks (n = 5, *<i>p</i><0.05, **<i>p</i><0.01). (B) Fold increase of total NK cells. NK cells were derived from total cells isolated from the primary 2-week co-cultures of hEB-derived cells with either MS-5/SP-HOXB4 or MS-5/EGFP control and then cultured under NK-cell differentiation condition for three weeks. NK cells were then numbered. Bars represent fold amplifications relative to day-0 control (un-co-cultured hEBs) (designated as 100%) (n = 5, *<i>p</i><0,05).